The student helicopter pilot stated that during a personal flight, he and a pilot departed the airport, flew to a ranch and returned. The pilot did not hold a flight instructor certificate. Upon return, they flew to the airport fuel facility to obtain fuel. A witness stated that the student pilot told him he was manipulating the flight controls at the time of the accident during a hover taxi and due to gusty wind conditions and not being comfortable, he transferred the flight controls to the pilot. The student pilot stated as the helicopter nearly touched down in front of the fuel facility, a big gust of wind, presumably a whirlwind, shot the helicopter straight up about 20-25 ft, and the helicopter did a quick 360° turn and rolled left before it came crashing down. The helicopter sustained substantial damage to the tail rotor, fuselage, and main rotor. The student pilot stated there were no mechanical malfunctions or failures of the helicopter that would have precluded normal operation.